U.S. patent number 3,978,995 [Application Number 05/522,724] was granted by the patent office on 1976-09-07 for mobile tier picking apparatus for a warehousing system.
This patent grant is currently assigned to Rapistan, Incorporated. Invention is credited to LeRoy Lubbers, Howard A. Zollinger.
United States Patent |
3,978,995 |
Zollinger , et al. |
September 7, 1976 |
Mobile tier picking apparatus for a warehousing system
Abstract
A warehousing system comprises an array of storage bins arranged
in vertical tiers with the tiers arranged in rows having access
aisles extending along the rows. A mobile vertical life moves along
the ends of the aisles and carries thereon a mobile transfer
vehicle which can be elevated by the mobile vertical lift to any
desired storage level and discharged therefrom onto rails extending
along each storage level of each access aisle. The self-powered
mobile transfer vehicle includes forks for transferring loads
between the vehicle and a storage bin. At least one of the transfer
vehicles in the system is a tier picking vehicle including a vacuum
operated picking head mounted to be lowered and raised between the
picking vehicle and a make-up transfer vehicle below the picking
vehicle. In one embodiment, the vacuum picking head is mounted on
extensible arms of the tier picking vehicle and can be extended
into a storage bin such that the tiers of articles picked directly
from a palletized load in a storage location can be transferred to
the make-up transfer vehicle in the same aisle and positioned below
and in alignment with the picking vehicle.
Inventors: |
Zollinger; Howard A. (Ada
Township, Kent County, MI), Lubbers; LeRoy (Grand Rapids,
MI) |
Assignee: |
Rapistan, Incorporated (Grand
Rapids, MI)
|
Family
ID: |
26988455 |
Appl.
No.: |
05/522,724 |
Filed: |
November 11, 1974 |
Related U.S. Patent Documents
|
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
332903 |
Feb 15, 1973 |
3866767 |
|
|
|
Current U.S.
Class: |
414/279;
414/281 |
Current CPC
Class: |
B65G
1/0414 (20130101) |
Current International
Class: |
B65G
1/04 (20060101); B65G 001/06 () |
Field of
Search: |
;214/16.4A,16.4B,16B,65SG |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
262,893 |
|
Jun 1968 |
|
OE |
|
1,292,581 |
|
Apr 1969 |
|
DT |
|
1,938,473 |
|
Apr 1971 |
|
DT |
|
703,068 |
|
Apr 1966 |
|
IT |
|
1,176,652 |
|
Dec 1969 |
|
UK |
|
218,390 |
|
May 1969 |
|
SU |
|
Primary Examiner: Spar; Robert J.
Assistant Examiner: Johnson; R. B.
Attorney, Agent or Firm: Price, Heneveld, Huizenger &
Cooper
Parent Case Text
This is a division, of application Ser. No. 332,903, filed Feb. 15,
1973 now U.S. Pat. No. 3,866,767 issued Feb. 18, 1975.
Claims
The embodiments of the invention in which an exclusive property or
privelege is claimed are defined as follows:
1. In a materials handling system including storage racks with an
array of storage locations for receiving and storing tiered
articles and including access aisles extending adjacent the storage
locations and having a pair of vertically spaced guide and support
means thereon extending along discrete storage levels to provide
access to an open end of each of the storage locations in the
system, means for transferring tiers of articles within the system
comprising:
a mobile tier picking vehicle for movement within a preselected
access aisle along the upper one of a pair of vertically spaced
guide and support means at a preselected discrete storage level
within said aisle to transfer tiered articles within the storage
aisle;
a picking head movably positioned on said tier picking vehicle for
picking tiers of articles from unitized loads of tiered articles in
said storage racks;
means for aligning in a predetermined manner a unitized load of
tiered articles stored within said system and said picking
head;
a separate independently operable mobile make-up vehicle dispatched
on the lower one of said pair of vertically spaced guide and
support means in said preselected aisle below and aligned under
said tier picking vehicle to receive picked tiers of articles from
said picking head of said mobile transfer picking vehicle; and
control means for moving said picking head into contact with said
tier of articles and for shifting the position of said picking head
to transfer said tier of articles from said unitized load to said
mobile transfer vehicle.
2. The system as defined in claim 2 wherein said tier picking
vehicle includes a frame having a hoist unit positioned thereon,
and means for coupling said picking head to said hoist unit such
that said picking head can be lowered to pick or deposit a tier of
articles and raised to transport said tier of articles.
3. The system as defined in claim 2 wherein said means for aligning
a unitized load and said picking head of said tier picking vehicle
comprises a retrieval mobile transfer vehicle dispatched in an
aisle level and storage location aligned below said tier picking
vehicle and including load transferring means thereon for
retrieving a unitized load from a storage bin and positioning said
load in said aisle where it is accessible to said picking head.
4. The system as defined in claim 1 wherein said means for aligning
a unitized load and said picking head of said tier picking vehicle
comprises an extensible boom positioned on said tier picking
vehicle and to which said picking head is coupled, and control
means for extending said boom into a storage bin to position said
picking head above a unitized load therein.
5. In a warehousing system having a plurality of access aisles
running along an array of storage bins for receiving and storing
unitized loads, said access aisles including pairs of vertically
spaced guide and support means therein, each guide and support
means associated with a single storage bin level, materials
handling apparatus comprising the combination of:
a mobile transfer vehicle movable along a lower one of a pair of
said guide and support means at any preselected discrete storage
level in an access aisle;
control means for actuating said mobile transfer vehicle to align
with a predetermined storage location in an access aisle;
a mobile picking vehicle movable along the upper one of said pair
of guide and support means of any preselected discrete storage
level and an access aisle;
a tier picking head for said picking vehicle, said head movable
between a lowered tier picking and releasing position and a raised
tier transferring position;
extensible and retractable boom means coupling said tier picking
head to said mobile picking vehicle for extending said tier picking
head into a storage bin above articles stored thereon for removal
of the uppermost tier of articles from the storage bin; and
means for sequentially controlling said boom means and said picking
head to extend said picking head into said storage bin, lower said
head into contact with the uppermost tier of articles in said bin,
raise and retract said picking head from said storage bin and then
lower said picking head for depositing the uppermost tier of
articles on said mobile transfer vehicle below said picking
vehicle.
Description
BACKGROUND OF THE INVENTION
The present invention relates to warehousing systems and
particularly to a system employing a mobile tier picking
vehicle.
When selectively picking cartons from palletized loads of cartons,
systems employing vacuum operated tier picking devices frequently
require that the palletized loads be brought to a fixed tier
picking location which includes a vacuum tier picking apparatus
that selectively removes a tier of cartons from the palletized
loads and transfers tier picked articles to a make-up pallet. The
remaining cartons on the picking pallet must then be returned to
storage by conventional load transferring means. U.S. Pat. No.
2,716,497 issued on Aug. 30, 1955 to E. A. Wahl et al., is
representative of a system employing a typical fixed tier picking
station. It is apparent that considerable inefficiency is inherent
in the design of such systems since palletized loads must be taken
out of storage, transferred to the picking station, returned to the
storage area and then reinserted into storage
Recently, it has been suggested to incorporate tier picking
mechanism on a stacker crane type of vehicle which can travel
within an access aisle and remove palletized loads from storage and
transfer tiers of articles from the removed picking pallet onto a
make-up pallet also on the crane. The remaining articles on the
picking pallet are then returned to storage. The stacker crane can
progress along the aisle tier picking different articles until an
entire pallet of tier picked articles has been loaded onto the
make-up pallet and then transfer the make-up load to an output
station for shipment or the like.
Although such a system represents an improvement over the fixed
tier picking arrangement, the use of stacker cranes limits the
through-put capacity of such a system since the vertically movable
apparatus generally will take up an entire access aisle thereby
prohibiting additional stacking cranes from operating in the aisle
for picking entire or partial pallet loads. Additionally, when the
make-up load is completed, the stacker crane and vacuum picker
thereon must travel to a discharge location to transfer the make-up
pallet thereby tying up the tier picking equipment during this
period.
The warehousing system described in detail in a copending
application entitled WAREHOUSING SYSTEM filed on July 17, 1972,
Ser. No. 272,287 now U.S. Pat. No. 3,880,299 and assigned to the
present assignee, incorporates a plurality of mobile transfer
vehicles adapted to be dispatched into access aisles of a storage
system and transfer unitized loads between the vehicle and storage
bins along the aisle. In this system, the mobile transfer vehicles
include means thereon for transferring loads between the vehicle
and the storage location to facilitate the automatic storing and
retrieving sequence of operation. One or more mobile vertical lifts
travel across the ends of the access aisles to transport the mobile
transfer vehicles to different aisle levels or aisles. As described
in detail in the above identified application, which is
incorporated by reference herein, such a system overcomes theh
through-put limitations inherent in a stacker crane or other known
warehousing systems.
SUMMARY OF THE INVENTION
The apparatus of the present invention overcomes the limitations of
prior tier picking systems by providing an independently movable
tier picking vehicle which can be a mobile transfer vehicle of the
type described in the above identified application with a
vertically movable tier picking head. In one embodiment, the tier
picking vehicle is controlled in conjunction with a pair of mobile
transfer vehicles positioned in an access aisle below the tier
picking vehicle. A first of the transfer vehicles operates to
retrieve a palletized load while the second (or make-up) mobile
transfer vehicle acts as receiving means receiving tiers of
articles from the tier picking vehicle which is shuttled above the
retrieving and makeup vehicles.
When tiers of different items are being picked, the retrieving
vehicle returns remaining unitized loads to the storage bin and
proceeds together with the tier picking vehicle and make up vehicle
to a different aisle position where a different unitized load is
removed from a storage bin and made accessible to the tier picking
vehicle.
The cycle can be repeated until the make-up vehicle has a completed
pallet load at which time it is dispatched to a discharge location
while the tier picking and retrievel vehicles can continue to
operate with a different, empty make-up vehicle. This method and
the apparatus used therewith eliminates the inefficiencies of
combining the tier picking, retrieving and make-up equipment on a
single vehicle or at a fixed location.
In one embodiment, the vacuum picking head of the tier picking
vehicle is mounted in a pair of arms extendible into a storage bin
above the unitized loads. In this system, the retrieval vehicle is
eliminated since the picking vehicle functions to retrieve the tier
of articles directly from storage.
It is an object, therefore, of the present invention to provide an
improved highly efficient tier picking method for picking selected
articles from different storage locations in a warehouse and for
palletizing the picked tiers of articles.
It is another object of the present invention to provide
independently movable mobile tier picking vehicles and make-up
vehicles.
An additional object of the present invention is to provide a tier
picking vehicle which is compatible with a warehousing system
employing a plurality of mobile transfer vehicles movable along
selected levels of each access aisle of the system.
A further object of the present invention is to provide
predetermined locations for discharging unitized loads made up of
tiers of different articles for further transfer by means of
separate mobile transfer vehicles.
Another object of the present invention is to provide an
independently movable mobile tier picking vehicle for transferring
tiers of articles within a warehouse system.
These and other objects of the present invention will become
apparent upon reading the followiing description thereof in
conjunction with the accompanying drawings in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic plan view of a warehousing system embodying
the present invention;
FIG. 2 is a schematic side elevation view of the warehousing system
of FIG. 1;
FIG. 3 is a fragmentary perspective view of the warehousing system
of the present invention;
FIG. 4 is a schematic side elevation view of one embodiment of the
present invention;
FIG. 5 is a fragmentary perspective view of the embodiment shown in
FIG. 4;
FIG. 6 is a schematic side elevational view of an alternative
embodiment of the invention;
FIG. 7 is a schematic side elevational view of another embodiment
of the invention; and
FIG. 8 is an electrical circuit diagram in block form of the
control system for the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now in detail to FIGS. 1 and 2, there is shown a
warehousing system comprising a plurality of storage racks 10
separated by aisles 12 therebetween which extend along the length
of the storage racks 10. The racks are divided into a plurality of
levels and individual storage bins which form an array of storage
locations adapted to receive unitized loads typically comprising
tiers of individual articles. Fire barriers 30 (FIG. 2) extend
horizontally through the storage rack area but not through the
transverse aisle 120 in which the mobile vertical lift 100
travels.
Each aisle level includes one or more storage bins 21P (one shown
for aisle 12' in FIG. 1) in which a supply of empty pallets are
stacked. As explained below, the pallets therein are singly
removable and are picked up by make-up vehicles as necessary. Each
aisle level further includes a flow rack 25 (one shown between
aisles 12" and 12' in FIG. 1) communicating between adjacent
aisles. The flow racks can be of conventional powered or gravity
design and as explained below, serve to transfer palletized loads
made up of tiers of articles from a tier picking aisle to an
adjacent aisle.
A transverse aisle 120 extends along one end of the aisles 12
between the two sections of storage racks, and a mobile vertical
lift 100 adapted to engage monorails 14 and 16 traverses aisle 120.
The mobile vertical lift (trans-aisle vehicle) 100 is adapted to
receive any one of a plurality of mobile transfer vehicles 200
which are dispatched into the aisles 12 of the storage system so
that materials can be transferred into and out of the storage bins
by the transfer vehicles 200.
The mobile vertical lift 100 operates between a home station
generally indicated at 300 which includes input and output stations
320 and 340, respectively, which serves as an interface between the
warehousing system and other systems such as a receiving station or
shipping station respectively. The warehousing system further
includes a transfer vehicle storage magazine 350 communicant with
the output station 340 and adapted to store transfer vehicles when
not in use. A retractable bridge 400 facilitates the movement of
transfer vehicles 200 between the output station 340 across the
monorail 16 and the input station 320 area when the mobile vertical
lift 100 is not at the home station.
The mobile vertical lift 100 includes a vertically movable lift
platform 150 thereon which has a carriage assembly which carries
the mobile transfer vehicles 200 by means of guide rails 154
adapted to receive guide wheels on the mobile transfer vehicles
200. The lift platform 150 is shown in FIG. 2 moving upwardly as
indicated by the arrow 152 to an aisle level where a transfer
vehicle 200 is in position to be received by the mobile vertical
lift 100. When the mobile vertical lift is in position, the guide
rails 154 are aligned with horizontal guide rails 18 extending
along the aisles 12 of the storage racks 10 such that the transfer
vehicle 200 can transfer between the mobile vertical lift 100 and
aisles 12.
The transfer vehicles 200 are self-powered and are guided within
the storage racks 10 along the aisles 12 by means of the guide
rails 18 at a predetermined vertical height such that palletized
loads 210 can be automatically transferred betwen storage locations
within the storage racks and the mobile transfer vehicles 200 by
transfer means carried on the vehicles 200. In FIGS. 1 and 2,
arrows accompanying the palletized loads 210 and the transfer
vehicles 200 indicate the direction of movement of the loads into
and out of storage and the transfer vehicle motion toward the
mobile vertical lift 100.
The mobile vertical lift 100 can be directly coupled to a control
station 330 (FIG. 1) by means of a festoon cable 325 as shown in
FIG. 2, to receive positional information from a computer to
control the movement of the vertical lift 100 and direct the
movement of the transfer vehicles 200. The cable 325 also provides
the mobile vertical lift 100 with operating power for its drive
motors. The mobile vertical lift can also be controlled
semi-automatically by employing a punched card or like system in
which an operator inserts such a card into a reader on the lift to
control its movement within the system. Likewise, it is possible to
manually control the positioning of the lift by carrying an
operator thereon and providing suitable operator controls.
Each mobile transfer vehicle 200 includes its own drive mechanism
and power supply such that it is self-powered in its motion within
the aisles 12. The input/output station rails (375 and 358) include
an electrical supply bus or collector bar and each mobile transfer
vehicle includes a contact shoe adapted to slidably engage the
collector bar such that when the transfer vehicle is at the home
station area, it can be externally powered to conserve the
electrical energy stored in its batteries. It is noted that such a
conventional power supply can be employed at various of the
warehouse areas including the access aisles if desired although in
the preferred embodiment, the transfer vehicles are self-powered
when in the aisles.
the warehousing system shown in FIGS. 1-3 includes at least one
tier picking vehicle 200V which comprises a mobile transfer vehicle
having a tier picking head 275 mounted thereto and movable such
that it can remove tiers of articles from a retrieval vehicle 200R
(FIG. 1) positioned in alignment an aisle below the picking
vehicle. This permits the transfer of the tier or a partial tier of
articles so picked to make-up vehicle 200M as explained in greater
detail below. Depending upon the size of the warehouse
installation, several tier picking vehicles 200V may be employed.
The make-up and retrieval vehicles 200M and 200R, respectively, are
generally the same as the remaining mobile transfer vehicles 200
and are designated by the suffixes M and R for the purpose of
discussing the operation of the tier picking system.
FIGS. 1 and 2 illustrate the use of the materials handling system
to interface with the input and output stations 320 and 340. The
input station 320 has a conveyor 322 for transferring materials
from a receiving station for example, in a warehousing facility to
the input station where materials are picked up by a mobile
transfer vehicle 200 at the input station 320 on guide rails 375.
The output station 340 has a conveyor 345 associated therewith
which receives materials from a transfer vehicle 200 at the output
station on rails 358 also associated with and extending into the
vehicle storage magazine 350. Conveyor 345 then transfers materials
to a shipping dock for example, that is associated with the
warehousing system.
In addition, the facility shown in FIGS. 1 and 2 may include
additional input and output means such as the guide rails 375 which
are adapted to guide transfer vehicles 200 to a different facility
such as an assembly line within the system. A shunting or stub
conveyor 385 may be located adjacent the rails 375 to receive
preselected loads from some of the transfer vehicles 200 and carry
them to a different area, such as a packaging station. Also,
another set of guide rails 395 may be provided at an opposite end
of the storage racks for guiding vehicles 200 to a repair facility,
maintenance facility, or any other of a number of different
facilities. Thus, it is seen by employing a self-powered transfer
vehicle 200, the vehicle itself may, under its own power and
programmed intelligence, move between the warehouse facilities
shown in FIGS. 1 and 2 to other facilities by means of rails 375
and 395 or may transfer loads thereon to various facilities as
indicated by the associated conveyors 322, 345 and 385.
Referring now to FIG. 3, there is shown a perspective view of a
portion of the warehousing system shown in FIGS. 1 and 2, showing a
cutaway portion of a mobile vertical lift 100 and a mobile transfer
vehicle 200 which can serve as a retrieval vehicle 200R or a
make-up vehicle 200M.
The storage racks 10 comprise vertical supports 20 and load
supports 22 that define individual storage bins 21 forming an array
along each aisle. The bins 21 are adapted to receive standard
palletized loads 210 made up of tiers 212 of articles as shown. As
noted above, one or more pallet bins 21P is provided at each
storage level of each access aisle to supply empty make-up pallets.
Suitable pallet dispensing means are provided in the bins 21P to
singly dispense make-up pallets to the make-up vehicles 200M.
The warehousing system is divided into dual sections of arrays of
bins 21 that are accessible from adjacent aisles 12. The guide
rails 18 form a portion of the horizontal support members for the
storage racks 10 as well as providing support for the transfer
vehicles 200. As een in FIG. 3, the carriage assembly 170 on the
mobile vertical lift 100 also includes guide rails 154 which are
adapted to be aligned with the rails 18 such that a transfer
vehicle 200 can be transferred from the storage rack 10 onto the
lifting platform 150 of the mobile transfer vehicle 100 on which
the carriage assembly rests.
All transfer vehicles 200, 200V, 200M and 200R include a drive
motor 250 coupled to guide wheels 270 which ride within the guide
rails 18. The vehicle construction and the drive control therefor
is described in detail in the copending application identified
supra. The vacuum picking vehicle which differs from the remaining
vehicles, is described below with reference to FIGS. 4 and 5.
Each of the transfer vehicles 200, 200M and 200R includes means 230
(FIG. 3) for transferring palletized loads 210 between a storage
bin 21 and the vehicle 200 or between the conveyors 322, 345 and
385 and the vehicle. In the preferred embodiment, means 230
comprise a pair of forks 240 each comprising a three-sectional
platform having a vertically movable base 232, a middle section 234
movable to either side of the vehicle 200, and a top section 236
extendible to either side in relation to the middle section 234 and
which fits under a palletized load 210 for lifting and transferring
the load to and from the vehicle 200.
The home station area 300 where the mobile transfer vehicles 200
are transferred to and from the mobile vertical lift 100, includes
a retractable bridge 400 as shown in FIG. 3. The bridge comprises a
pair of guide rails 418 mounted above the monorail 16 on which the
mobile vertical lift travels and which are lowerable and
retractable under the guide rails 375 shown in FIGS. 1 and 3. When
the mobile vertical lift 100 enters the home station area 300, the
tracks 418 are retracted out of the way so as not to obstruct the
movement of the mobile vertical lift. This is accomplished by
mounting the guide rails 418 of the bridge 400 on a platform 420
which is mounted to an additional platform 430 by means of a pair
of actuation cylinders 425. This arrangement allows the platform
420 to be elevated and lowered in relation to the platform 430.
Platform 430 is at approximately ground level and is mounted by
means of guide wheels within a pair of tracks 440 such that it is
longitudinally movable in a direction parallel to the tracks 375
and perpendicular to the monorail 16.
A motor 445 with a drive belt 450 coupled to the platform 430 can
be actuated to cause the platform 430 and, therefore, the platform
425 and rails 418 thereon to be drawn to the left in FIG. 3 out of
the way of mobile vertical lift 100, once the rails 418 have been
lowered by means of the cylinders 425. The bridge 400 is positioned
when the mobile vertical lift 100 is not at the home station to
provide a transfer path for the mobile transfer vehicles 200 from
the output station 240 into the input station 320. The bridge also
allows a transfer vehicle 200 to receive a palletized load 210 from
the input station 320 or to move along the tracks 375 to transfer
loads to the stub conveyor 385 or otherwise operate between the
input and output stations 320 and 340, respectively, without
requiring the presence of the mobile vertical lift 100. By so
designing the system, the transfer vehicles 200 can be utilized to
their maximum efficiency as can the mobile vertical lift 100.
Both the guide rails 418 of the bridge 400 and the guide rails 154
of the carriage assembly 170 associated with the mobile vertical
lift 100 have locating means 410 and 160, respectively, which are
employed in conjunction with tapered ends of the guide rails 18 in
the storage racks 10 to accurately align the guide rails 154, 418
with the storage rack guide rails 18 such that the transfer
vehicles 200 can easily be transferred into and out of the storage
rack aisles 12. The guide rails 18 each include stops 24 (only two
shown in FIG. 3) at the ends of the rails 18 adjacent the aisle 120
to prevent the vehicles from accidentally slipping from the aisle
level when the mobile vertical lift 100 is not in position to
receive the vehicle The operation of the transfer vehicles and
mobile lift to transfer entire unitized loads 210 into and out of
storage is described in detail in the above-identified copending
application and will not be repeated here. A description of the
picking vehicle with a vacuum picking head to transfer full or
partial tiers 212 of articles is now presented.
Referring to FIGS. 4 and 5, there is seen one embodiment of the
present invention in which the picking vehicle 200V is dispatched
from a mobile vertical lift to an aisle level above the retrieval
and make-up vehicles 200R and 200M, respectively. Vehicle 200V is
controlled to move along the rails 18 on wheels 270 to shuttle
between the tier picking position shown in FIG. 4 (and in phantom
form in FIG. 5) and the tier dispatching position shown in solid
lines in FIG. 5.
The picking vehicle 200V comprises a mobile transfer vehicle drive
motor and control unit 250 mounted on a frame 245 and including a
column detecting means 265 such that the vehicle can be alternately
positioned in alignment with predetermined storage bin columns 20.
In place of the shuttle fork, however, the vehicle includes a
vertically movable platform 280 coupled to frame 245 by means of
suitable support cables 285 which are raised and lowered by means
of a motor driven hoist and guide pulley unit 290 positioned on the
frame. Mounted on the platform 280 is picking means which, in the
preferred embodiment, is a vacuum operated picking head 275
including a blower motor 277 for forming a partial vacuum at the
gripping surface of the head which communicates with the top
surface of a tier of articles to be picked and transferred from the
retrieval to the make-up vehicles. Other picking means such as
carton clamps or the like may also be used for tier picking.
Frame 245 includes a central aperture 246 which permits the vacuum
head to retract to a fully raised position when vehicle 200V is in
motion. The platform 280 seats within the frame in this position to
hold the tier picked articles in a stable position during their
transfer. This arrangement eliminates swinging of the articles from
cables 285. The vacuum head 275 mounted on the mobile tier picking
vehicle 200V can be of the type described in U.S. Pat. Nos.
3,313,568 issued to D. A. Fogg on Apr. 11, 1967, or 3,598,439
issued to Ernest A. Dahlquist et al. on Aug. 10, 1971; both of
which are assigned to the present assignee.
The make-up vehicle 200M can be hitched to the retrieval vehicle
200R by means of a tongue and hitch combination such that only one
of the vehicles need be powered and controlled. More frequently,
however, it is desirable to control the vehicle independently such
that once the palletized load on the make-up vehicle has been
completed, it can be dispatched to one of the flow racks 25 for
discharging full pallets thereon.
OPERATION
Referring now to the electrical control circuit diagram of FIG. 8
in conjunction with FIGS. 4 and 5, a master control computer 460
dispatches the picking vehicle 200V to the aisle level above the
articles to be tier picked in vertical alignment with the storage
bin. Information from the computer is fed to the vehicles through
information transfer panels 461' positioned on the vehicles via
panels 461 located on a mobile vertical lift or at the aisle
ends.
The retrieval vehicle 200R is dispatched to the storage location
and make-up vehicle 200M is dispatched to the same aisle level to a
storage bin two bins away from the stored articles to be picked
(since each of the transfer vehicles is slightly longer than the
width of a single bin). The control circuits and their operation to
dispatch the vehicles to desired storage positions in the warehouse
is discussed in detail in the copending application identified
supra and will not be repeated here. It is noted, however, that
once the vehicles are initially dispatched, the retrieval vehicle
generally serves as the intelligence carrying vehicle and serves to
control the shifting and repositioning of the picking and make-up
vehicles as described below. Once vehicle 200R is positioned, its
forks are actuated automatically to retrieve the entire pallet load
or whatever articles remain on the pallet in the desired storage
bin and bring them onto the vehicle where they are within the aisle
and accessible to the picking vehicle aligned overhead.
After the pallet is aligned on the retrieval vehicle, the retracted
shuttle forks actuate a light 462 on vehicle 200R which is directed
toward an optical sensor 464 on the aligned picking vehicle 200V.
Detector 464 applies a control signal to the picking vehicle logic
and control circuit 470 to initiate the sequence of operation of
the picking head and the vehicle. It is noted here that the control
circuit 252 maintains the retrieval vehicle in position once the
pallet is retrieved and moves the retrieval vehicle to the next
picking location only after the pallet has been returned to
storage.
Circuit 470 actuates hoist unit 290 which lowers platform 280 with
the vacuum picking head 275 thereon until the picking head contacts
the uppermost tier of articles on vehicles 200R. The vacuum head
blower motor 277 is continuously operated and the selectively
operated blast gate 279 (FIG. 8) which forms an integral part of
the picking head, is in a position to apply a partial vacuum to the
picking surface 275 (FIG. 4) of the head. As the picking head rests
on the uppermost tier of articles, a slack cable detector 464
physically positioned on frame 245 to detect the slack in cables
285 is actuated and applies a signal to circuit 470 which reverses
the hoist unit 290. The picking head and platform 285 are then
raised to the uppermost position lifting the tier of articles from
the retrieval pallet.
In the raised position, platform 280 trips a limit switch 466
positioned on frame 245 to deactuate hoist unit 290 and actuate the
vehicle drive motor 250. Circuit 470 includes a program or
subroutine 470' for controlling drive motor 250 to shift the
vehicle down two storage bins as indicated by column detector 265
and then returning vehicle 200V to the aligned position over
vehicle 200R after the picked tier has been released. The hardware
forming the subroutine 470' can be of conventional design
incorporating storage and shift registers together with comparators
to provide a position control signal to the drive motor 250.
Once the picking vehicle 200V is aligned with the tier receiving
means comprising make-up vehicle 200M; a light source 279 on
vehicle 200M directs a beam of light to a detector 465 on vehicle
200V verifying the alignment of the vehicles. Detector 465, in
response to the received light, applies a signal to logic circuit
470 which initiates the transfer sequence. Hoist unit 290 is
actuated by circuit 470 to lower the picked tier of articles onto
the pallet positioned on the make-up vehicle. When the slack cable
condition is again detected by sensor 464', the blast gate 279 is
actuated by circuit 470 to shut off the vacuum to the picking
surface 276 of the head thereby causing the tier of articles to be
deposited on the awaiting pallet. The blast gate is opened after
the picking head is raised to trigger switch 466.
After a momentary delay allowing the articles to be deposited onto
the make-up pallet, the hoist unit is reversed by the logic and
control circuit 470 and upon its retraction into the frame of the
picking vehicle 200V, limit switch 466 is again actuated generating
a signal applied to circuit 470 which causes the drive motor to
shift the vehicle into an aligned position once again over the
retrieval vehicle 200R.
Once vehicle 200V has reached the aligned position detected by the
column detector 265, control circuit 470 actuates a light 266 on
the picking vehicle which is directed toward a light sensitive
detector 267 on the retrieval vehicle 200R. If more than one tier
of articles is to be picked, detector 267 causes the control
circuit 252 to once again actuate light 462 which in turn is sensed
by detector 464 on vehicle 200V to initiate another cycle of
operation of the picking head and vehicle.
In the event that only a single tier is to be picked, detection of
the light 266 by sensor 267 causes the actuation of a control light
268 on the retrieval vehicle 200R. This light is directed toward a
light sensitive detector 269 on vehicle 200V which is employed to
provide a control signal to the logic and control circuit 470 which
in turn signals the vehicle 200V to return to an aisle and where
the information transfer panel 461' is aligned with an information
transfer panel 461 to receive additional information as to the next
picking location. As discussed in the copending application
identified above, vehicle 200V can be programmed, however, for
automatic successive picking locations in which case the actuation
of sensor 269 causes the circuit 470 to actuate drive motor 250 to
proceed to transport the vehicle to the next picking location.
As vehicle 200V is transferring to the next picking location,
vehicle 200R which has received a signal from the picking vehicle
via sensor 267, either maintains the pallet in an available
position for the picking vehicle (in the event that more than one
tier is to be picked) or if only one tier is being picked, is free
to return the remaining articles on the pallet to the storage bin
as soon as the picking vehicle has removed the single tier. Once
the empty shuttle forks have been retracted onto the vehicle,
control circuit 252 controls the vehicle which then proceeds to the
next picking or other desired location in the system.
The make-up vehicle 200M on which the tier or tiers of articles
have been deposited can either transfer the picked tier of articles
to one of the aisle end flow racks 25 (FIG. 1) or can follow the
retrieval vehicle 200R to the next picking location. As soon as the
make-up vehicle has received the last tier of articles from the
picking vehicle, it is free to move independently of the picking
vehicle and can return to the aisle end for transfer by the mobile
vertical lift. In order to automatically control the make-up
vehicle 200M once initially positioned, a light source 272 on the
retrieval vehicle 200R directs a beam of light to a light sensitive
detector 274 positioned on vehicle 200M. Light 272 will be
activated in the event it is desired to send the make-up vehicle
200M to an aisle end to discharge the completed pallet thereon.
Upon receipt of a signal by sensor 274, it develops a control
signal applied to the control circuit 272 of vehicle 200M to cause
the vehicle to travel to the flow rack and discharge its pallet and
return to an aisle end to await further programming via panels 461,
461'.
In the event, however, that it is desired to have the make-up
vehicle follow the mobile transfer vehicle to the next picking
location and stop in an aligned position two bins away, a second
light source 276 on the retrieval vehicle 200R is activated and
directs a beam of light to a light sensitive detector 278 on
vehicle 200M. Sensor 278 is also coupled to the control circuit 272
of vehicle 200M and generates a signal causing the vehicle to move
the same number of bins as the retrieval vehicle moves and stop
once a retrieval vehicle has been positioned and light 276
extinguished.
In this manner, the retrieval, picking, and make-up vehicles repeat
the cycle of operation and travel along an aisle to selected
storage locations to tier pick articles under the control of a
computer inventory system.
Once the pallet on the make-up vehicle is completed (for example,
when five tiers have been picked), the make-up vehicle can also be
dispatched by vehicle 200R to an end of the aisle where it can be
picked up by a mobile vertical lift which then transfers the
vehicle to an input or output station of the system as described in
the copending application identified supra. Usually, however, the
make-up vehicle will be dispatched to the flow rack 25 where it
discharges the completed pallet to an adjacent aisle where another
mobile transfer vehicle will pick up the completed pallet and
transfer it to a mobile vertical lift thus freeing the make-up
vehicle for further duty within the same aisle.
The retrieval and make-up vehicles are initially dispatched within
an aisle by the computer to maximize their picking efficiency. In
the event it becomes necessary to switch their positions, as for
example when picking at opposite ends of the aisle, it is possible
to reverse the interface detectors such that the make-up vehicle
becomes the retrieval vehicle and vice versa. In such case, the
vehicles 200R and 200M would carry identical control circuits and
the light sources and detectors would be dual operating units.
In place of controlling the picking vehicle 200V with the
conventional mobile transfer vehicle control mechanism to shuttle
between aligned positions above the retrieval and make-up vehicles,
a picking vehicle 200V' (FIG. 6) can be fabricated with an
elongated frame 245' including a carriage assembly 248. In this
embodiment, the vertically movable platform 280 to which the vacuum
head is mounted is suspended from carriage 248 by cables 285 in the
same manner as shown in FIGS. 4 and 5. The carriage assembly can be
of conventional design including for example, fixed gear racks
mounted on the inner sides of frame 245'. Rotatable drive gears on
the carriage are employed for coupling the carriage to the racks
such that the carriage can be reciprocated between the end
positions.
In the embodiment shown in FIG. 6, the make-up and retrieval
vehicles are controlled in the same manner as those employed in the
FIGS. 4 and 5 embodiment and the elongated frame 245' for the
picking vehicle is centered above the retrieval and make-up
vehicles such that the vacuum head will be aligned with one of the
vehicles when the shuttle carriage 248 is at an end position. The
same general control and drive for the vertically movable platform
can be employed in the FIG. 6 embodiment as that employed in the
FIGS. 4 and 5 embodiment. The only difference is illustrated in
FIG. 8 in dotted lines where it is seen that the logic circuit 470
controls a drive motor 247 for the carriage in place of the vehicle
drive motor during the tier picking operation. Limit switches 247'
deactivate motor 247 when the carriage reaches an end position.
Still a further embodiment of a picking vehicle 200V" is
illustrated by the schematic diagram of FIG. 7. In this embodiment,
the retrieval vehicle is eliminated by providing a picking vehicle
with an extension boom 295 which houses the vertically movable
platform 280 and picking head 275 mounted thereto. Boom 295 is
extended directly into a storage bin in the space above the stored
articles. The vacuum head is then lowered into contact with the
uppermost tier of articles of the stored pallet. The vacuum head is
then raised and the boom retracted under the picking vehicle to
center the picked tier of articles within the aisle. In this
embodiment, the make-up vehicle is positioned in the aisle in which
the stored articles are located and the picking vehicle is
positioned in the aisle above the make-up vehicle. The extensible
boom 295 is positioned under the frame of the vehicle so that it
will not interfere with the guide rails 18 of the system.
Boom 295 can be the same type of structure with drive mechanism
similar to the shuttle fork for the mobile transfer vehicles and
which is described in detail in a copending applicatioon entitled
MOBILE TRANSFER VEHICLE AND LOAD TRANSFERRING MEANS THEREFOR, Ser.
No. 272,134, filed on July 27, 1972, and assigned to the present
assignee. In the FIG. 7 embodiment, the shuttle fork to which the
cable lifting mechanism is mounted is positioned under the frame
instead of above the frame as described in the above identified
copending application which is incorporated herein by
reference.
The vacuum head for vehicle 200V" is controlled by a circuit
essentially the same as that shown for the vehicle 200V in FIG. 8.
Since no retrieval vehicle is necessary, a light is positioned on
the make-up vehicle to signal a detector on the picking vehicle to
initiate the tier picking operation once the two vehicles are
positioned in alignment within the aisles. The control 296 for the
boom extension can be the same as that used for the shuttle forks
in the mobile transfer vehicles and is illustrated by broken lines
in FIG. 8. Vehicle 200V" can be used independently under control of
the computer for shifting single tiers of articles between
different storage locations in the warehouse system. Likewise,
individual tiers of articles can be taken to the flow racks 25 or
other receiving areas in the system in much the same manner as the
mobile transfer vehicles transfer entire pallet loads.
Various modifications to the embodiments shown can be made by those
skilled in the art. For example, the vertical movement of the
picking head can be accomplished by any suitable conventional
mechanism. Additionally, the specific control including the optical
interface between the vehicles can be modified to provide the
desired results. In some installations, it may be desirable to
provide manual control of the picking, retrieval and make-up
vehicles. In such systems, one or more of these vehicles carry an
operator who controls the movement of the vehicles in the aisles.
The automatic alignment features can, however, be used for accurate
final adjustment if desired. Thus, any desired degree of automation
from the fully automatic mode described in the preferred embodiment
to a fully manual system can be employed in the system of the
present invention. These and other modifications to the present
invention will, however, fall within the scope of the present
invention as defined by the appended claims.
* * * * *